Table 1.
Characteristics of children from two birth cohorts (mean ± standard deviation, unless otherwise indicated).
| Variable | Cohort 1 (N = 101) | Cohort 2 (N = 99) |
|---|---|---|
| Obstetric and neonatal data | ||
| ΣPCBb concentration in pregnancy serum (μg/g lipid)c | ND | 1.22(0.71-1.87)a |
| Duration of exclusive breast-feeding (months) | 3.5 ± 1.9 | 3.5 ± 2.1 |
| Duration of total breast-feeding (months) | 7.0 ± 4.3 | 7.7 ± 5.5 |
| First examination | Year 1986/7 | 1994/5 |
| Age (years) | 6.7 ± 0.2 | 4.6 ± 0.1 |
| Weight (kg) | 24.8 ± 4.0 | 19.0 ± 2.4 |
| Height (cm) | 123 ± 5 | 107 ± 4 |
| Body mass index (kg/m2) | 16.4 ± 1.8 | 16.5 ± 1.4 |
| ΣPCB concentration in serum (μg/g lipid)c | 1.71 (1.06-2.66)a | 0.95 (0.50-1.79)a |
| Second examination | ||
| Age (years) | 13.8 ± 0.3 | 7.6 ± 0.1 |
| ΣPCB concentration in serum (μg/g lipid)c | 0.86 (0.47-1.62)a | 0.79 (0.46-1.43)a |
| Body weight (kg) | 54.0 ± 10.8 | 26.3 ± 4.3 |
| Height (cm) | 163 ± 7 | 126 ± 5 |
| Body mass index (kg/m2) | 20.2 ± 3.3 | 16.4 ± 1.8 |
a
Geometric mean with 50% range in parenthesis.
b
Sum of the major polychlorinated biphenyl congeners 138, 153, and 180 multiplied by 2.0.